Conventionally, in a thermal power plant or the like, for example, fossil fuel such as coal, oil, or LNG is burned in a boiler to generate steam, and power generation is performed by turning a turbine using this steam. Further, in such a thermal power plant or the like, since a large amount of exhaust gas containing CO2, which is one of the greenhouse gases contributing global warming, is exhausted with combustion of the fossil fuel, a facility for treating this exhaust gas, particularly, recovering and removing CO2 from the exhaust gas, is provided.
Further, a system that recovers CO2 (a CO2 recovery apparatus) includes, for example, a quencher (a pre-treatment apparatus) 2 that performs pre-treatment of an exhaust gas 1, an absorber (an absorption apparatus) 4 that brings the exhaust gas treated by the quencher 2 and having a low temperature into contact with a CO2 absorption liquid (lean solvent 3) to absorb and remove CO2 from the exhaust gas 1, and a regenerator (a regeneration apparatus) 6 that separates and recovers CO2 from the CO2 absorption liquid (rich solvent 5) having absorbed CO2 in the absorber 4, as shown in FIG. 15 (e.g., see Patent Document 1 and Patent Document 2).
Further, the CO2 absorption liquid 3 after CO2 has been recovered in the regenerator 6 is sent to the absorber 4 and used to absorb and remove CO2 from the exhaust gas 1 again. In other words, this CO2 recovery system is configured to circulate the CO2 absorption liquids 3 and 5 in an absorption liquid circulation path 7 between the absorber 4 and the regenerator 6 and repeat the absorption of CO2 into the CO2 absorption liquid 3 and the recovery of CO2 from the CO2 absorption liquid 5 to recover and remove CO2 from the exhaust gas 1, which is sequentially supplied.